I'm trying to keep up-to-date on the RNC's missing emails. What I know so far: Representative John Conyers (D-MI) and Senator Patrick Leahy (D-VT) exchanged letters with White House Counsel Fred Fielding. They are chairmen of the House and Senate Judiciary Committees, respectively. They want Republican National Committee emails, especially those on the gwb43.com. Fielding responded that the White House is steadfast in its refusal to let the RNC supply the emails. From ThinkProgress, White House Says It Will Not Turn Over RNC Emails
Representative Conyers and subcommittee chairwoman Linda Sanchez (D-CA) wrote to the chairman of the RNC (4/12/07) to demand White House officials' emails related to the U.S. attorney firings investigation. You can see their letter on TPMMuchraker here:
House Dems Press for RNC Emails
The White House claims executive privilege protects the RNC emails. What exactly is this executive privilege that Bush so easily invokes? Well, it's the power claimed by the POTUS and other members of the executive branch to resist certain search warrants and other encroachments on their purview.
Executive privilege is not mentioned anywhere in the Constitution but the Supreme Court confirmed the legitimacy of the doctrine in the United States v. Richard Nixon (418 U.S. 683) back in 1974, but only to the extent of confirming that it can be invoked when the oversight of the executive branch would impair the branch's national security concerns. Before this case, executive privilege was a relatively untested legal doctrine.
The United States v. Richard Nixon was a unanimous 8-0 decision. It set a crucial precedent limiting the power of any U.S. President.
More about this decision and how it can help get those emails later.